The most common dispensers for viscous fluids today are the venerable collapsible tube containers. These containers are usually fabricated of soft metal or plastic and have a screw cap to seal the tube. The fluid is dispensed by applying pressure to the tube from the bottom until a sufficient quantity is expelled. These dispensers have been commonly used on viscous fluids such as toothpaste, creams, pastes, jellies, etc. However, such dispensers present some problems for applications such as, for example, medical applications or contraceptive jellies and creams where a measured quantity of the fluid must be dispensed or a quantity of fluid is to be applied to remote locations not readily visible or accessible. Since conventional collapsible tubes have no inherent structure for providing predetermined quantities, extension tubes or syringes must be incorporated to avoid spillage and to insure correct application. See, for example, U.S. Pat. No. 2,709,436 to Lynn. Where simple extension tubes are used, expulsion of the fluid must be controlled by the user and the quantity must be judged visually.
Various other structure is known in the art for dispensing viscous fluids. These include syringes, spring loaded dispensers, pneumatic dispensers and screw-type dispensers. Syringes are commonly known in the art but require separate structure or elaborate designs. See, for example U.S. Pat. No. 2,793,792 to Pilkington.
Spring loaded dispensers, pneumatic dispensers and screw-type dispensers employ a means for applying pressure to a rigid container which exerts a force to drive the viscous fluid out of the container. See. e.g. U.S. Pat. Nos. 1,119,033 to Paddock, 703,250 to Grimm, 1,084,537 to Clark and 4,323,175 to Eckert. These dispensers are hampered by their difficulty in conveniently dispensing a premeasured quantity of viscous fluid at both proximate and remote locations.